Field glass



FIG. 1 is a left view of the invention;

FIG. 2 is a right view of the invention;

FIG. 3 is a perspective view of the invention;

FIG. 4 is a front view of the invention;

FIG. 5 is a top view of the invention;

FIG. 6 is a bottom view of the invention; and,

FIG. 7 is a back view of the invention.

The broken lines form no part of the claimed design. 

The ornamental design for a field glass, as shown and described. 